A method includes generating a correlation vector of baseband-signal vectors based upon signals received from a plurality of sensor devices, generating a generalized Hankel matrix R representing a covariance matrix to which a spatial averaging is applied based upon the correlation vector, generating a kernel matrix Ω1, which is a projection matrix onto noise subspace, by performing linear operation using submatrices R1 and R2 of the generalized Hankel matrix R, generating a kernel matrix Ω2, which is orthogonal with the kernel matrix Ω1, and estimating a direction of arrival of a signal based upon the kernel matrices Ω1 and Ω2.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for estimating a direction of arrival comprising: generating a correlation vector of baseband-signal vectors based upon signals received from a plurality of sensor devices; generating a generalized Hankel matrix R representing a covariance matrix to which a spatial averaging is applied based upon the correlation vector; generating a kernel matrix Ω 1 , which is a projection matrix onto noise subspace, by performing linear operation using submatrices R 1 and R 2 of the generalized Hankel matrix R; generating a kernel matrix Ω 2 , which is orthogonal with the kernel matrix Ω 1 ; and estimating a direction of arrival of a signal based upon the kernel matrices Ω 1 and Ω 2 .
2. The estimating method according to claim 1 , wherein: the estimating is based on an angular spectrum defined using one of the kernel matrices Ω 1 and Ω 2 as a numerator and the other as a denominator.
3. The estimating method according to claim 1 , wherein: the estimating is based on an algebraic equation using the kernel matrices Ω 1 and Ω 2 .
4. A direction-of-arrival estimating apparatus comprising: a first matrix generating unit configured to generate a correlation vector of baseband-signal vectors based upon signals received from a plurality of sensor devices, and to generate a generalized Hankel matrix R representing a covariance matrix to which a spatial averaging is applied based upon the correlation vector; a second matrix generating unit configured to generate a kernel matrix Ω 1 , which is a projection matrix onto noise subspace, by performing linear operation using submatrices R 1 and R 2 of the generalized Hankel matrix R and to generate a kernel matrix Ω 2 , which is orthogonal with the kernel matrix Ω 1 ; and an estimating unit configured to estimate a direction of arrival of a signal based upon the kernel matrices Ω 1 and Ω 2 .
5. The direction-of-arrival estimating apparatus according to claim 4 , wherein the second matrix generating unit includes, an operator calculating unit configured to calculate a linear operator Γ=(R 1 R 1 H ) −1 R 1 R 2 H using the submatrices R 1 and R 2 of the generalized Hankel matrix R, where −1 represents an inverse matrix, and H represents a complex conjugate transposition, and a propagator-matrix calculating unit configured to calculate a propagator matrix Π=[Γ, −I] T or an orthogonal propagator matrix Π′=Π(Π H Π) −1/2 using the linear operator Γ and a unit matrix I, where T represents transposition and −½ represents an inverse of square root (√), and wherein the kernel matrix Ω 1 is generated using the propagator matrix Π or the orthogonal propagator matrix Π′.
6. The direction-of-arrival estimating apparatus according to claim 5 , wherein the second matrix generating unit further includes a scaling-matrix calculating unit configured to calculate a scaling matrix Λ=R 2 R 2 H −R 2 R 1 H Γ using the submatrices R 1 and R 2 of the generalized Hankel matrix R and the linear operator Γ, and wherein the kernel matrix Ω 1 is generated using an inverse matrix of the scaling matrix Λ and the propagator matrix Π or the orthogonal propagator matrix Π′.
7. The direction-of-arrival estimating apparatus according to claim 6 , wherein the second matrix generating unit generates the kernel matrix Ω 1 by linearly-combining a kernel matrix calculated using the propagator matrix Π or the orthogonal propagator matrix Π′ with a kernel matrix generated using the inverse matrix of the scaling matrix Λ and the propagator matrix Π or the orthogonal propagator matrix Π′.
8. The direction-of-arrival estimating apparatus according to claim 4 , wherein, when the number of the sensor devices is N and the number of incoming signals received at the sensor devices is M, the first matrix generating unit extracts, as first subvectors, combinations of continuously arranged (N−M) components, not including autocorrelation components, from subvectors whose elements are correlation vectors of the baseband signals having identical complex conjugate components and at least (N−M) multiple components continuously arranged up to the autocorrelation components, extracts, as second subvectors, combinations of continuously arranged (N−M) components, not including the autocorrelation components, from subvectors whose elements are the correlation vectors having identical complex conjugate components and at least (N−M) multiple components continuously arranged after the autocorrelation components, generates a first matrix group and a second matrix group in the order ((N−M)×M) in which the first vectors and the second vectors having identical complex conjugate components are arranged such that components having matching phase relationships are disposed at same element positions, and generates the generalized Hankel matrix R using at least one of a first matrix R f1 generated by adding together the first matrix group and a second matrix R f2 generated by adding together the second matrix group.
9. The direction-of-arrival estimating apparatus according to claim 8 , wherein the first matrix generating unit uses a first coefficient matrix and a second coefficient matrix for matching magnitudes of vectors between column vectors of the first matrix R f1 and the second matrix R f2 to calculate a Hadamard product of the first matrix R f1 and the first coefficient matrix and a Hadamard product of the second matrix R f2 and the second coefficient matrix.
10. The direction-of-arrival estimating apparatus according to claim 8 , wherein the first matrix generating unit generates complex conjugate matrices of the first matrix R f1 and the second matrix R f2 , uses the products of the complex conjugate matrices and anti-diagonal unit matrices to generate matrices R b1 and R b2 , and uses the first matrix R f1 , the second matrix R f2 , and the matrices R b1 and R b2 to generate the generalized Hankel matrix R.
11. The direction-of-arrival estimating apparatus according to claim 4 , wherein the estimating unit is further configured to estimate on the basis of an angular spectrum defined using one of the kernel matrices Ω 1 and Ω 2 as a numerator and the other as a denominator.
12. The direction-of-arrival estimating apparatus according to claim 4 , wherein the estimating unit is further configured to estimate on the basis of an algebraic equation using the kernel matrices Ω 1 and Ω 2 .
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
August 30, 2010
June 19, 2012
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